Field of the Invention
The present invention relates to liquid ejection heads and methods of producing the same.
Description of the Related Art
A liquid ejection head used in a liquid ejection apparatus such as an inkjet recording apparatus may include a structure configured to prevent entry of bubbles or foreign substances in a liquid. Japanese Patent Laid-Open No. 2000-94700 discloses a method of forming a membrane filter, which is configured to prevent entry of bubbles and foreign substances, in a liquid ejection head, concurrently with an ink supply portion. In the invention described in Japanese Patent Laid-Open No. 2000-94700, an ink passes through openings in the membrane filter, i.e., the openings in the membrane filter serve as liquid supply openings. The openings are desired to have the smallest possible diameter and to be arranged at the smallest possible intervals to prevent entry of foreign substances, for example.